HP and Sun Microsystems claimed the new chip systems would propagate vendor lock-in and lead to a load of compatibility issues.

"At a time when TCO and maximizing return on investments are paramount, IBM continues to push proprietary architectures with limited customer choice," HP said in comments to the press after IBM's announcement. "Linux on Power hasn't demonstrated market
acceptance, and IBM has no support at all for Windows on Power. What choices will customers really have if they go with IBM Power5?"

But one analyst familiar with IBM's architecture and plans came to IBM's
defense. Illuminata President Jonathan Eunice, who said IBM's move is a
compelling one in the Unix space, was quick to point out that supporting
Itanium and Windows does not necessarily make one an "open" company.

"HP would prefer customers to choose Itanium, a chip that is supposedly not
proprietary because it is manufactured by Intel ," Eunice told
internetnews.com. "A chip produced by just one company is
proprietary, no matter what company produces it. Indeed, both [Sun's] SPARC and
Power are produced by multiple fabricators, and their architectures/designs
are in fact more openly available for inspection and license than is
Itanium."

The new Power5 systems, scheduled to ship
August 31, will include the 2-way p5-520, the 4-way p5-550 and the
16-way p5-570, which will also be released as an Express edition.

Key features include a new modular design for the Power5 machines and
"micro-partitioning," which was borrowed from the company's mainframe suite
and allows 10 virtual servers to run on one processor.

Ravi Arimilli, IBM Research Fellow and chief architect of eServers, said the features, part of a "disruptive design change" by IBM, are ones that customers asked IBM about because they were not able to get them from rivals HP and Sun.

"With Power5, users can gain a significant amount of performance, which removes the myth that you have to do a brand new architecture to gain more
value," Arimilli said at a recent press briefing. "There's been a big push
for architecture changes to provide more value for customers."

HP also called into question the "game-changing performance" IBM promised to bring with Power, and questioned some of its benchmarks on the system. For example, in a TPC-C benchmark of the IBM DB2 Universal Database, the
16-way p5-570 server beats a 16-way HP Integrity server by 269 percent and a
64-way machine from HP by 49 percent.

Dimitris Dovas, worldwide product marketing manager of Business Critical Systems at HP, told internetnews.com that IBM's practice of trotting out impressive benchmarks is nothing new and noted that the current high-end p690 UNIX server has a "great TPC-C number, but nothing more than that."

"But when we start to peel the onion, we learn that this is a combination of proprietary stacks and that they tune their architecture to deliver these
results," Dovas said. "They always have tricks where they're pulling one or
two great numbers but it doesn't address the customer challenge, which is:
'give me real life performance with my everyday application.'"

Dovas also questioned IBM's operating system compatibility, and wondered if AIX
applications would have to be rewritten to take advantage of the new Power5 and
AIX 5L 5.3, the latest OS driving the Power5 machines.

IBM said in a statement that only minor recompiling would
be needed and that "applications move from Power 4 to Power 5 as seamlessly
as switching channels with your remote."

Going forward, Dovas said HP will have new server news as the Intel Madison
roadmap becomes more fleshed out. HP will release new machines based on
Intel's Madison 9M, the 9 megabyte L3 cache version of Intel's Madison IA-64
CPU, slated for a Q3 release.

HP wasn't alone in the competitive joust. Sun
Microsystems also questioned Power5's compatibility and coding issues,
among other things.

"For 11 straight years, Sun has protected our customers' IT investments by
ensuring application compatibility across server generations and upgrades to
new technologies," Singer said. "IBM broke compatibility when moving to
its Power4 servers, so customers should question IBM's track-record on
upgrade compatibility when considering the new Power5-based servers."

Singer is referring to IBM's breaking of 64-bit application compatibility
between AIX 4.3.3 and AIX 5L 5.1 upgrade in order to run Power4. But Illuminata's Eunice noted
that while IBM's move required application recertification from independent
software vendors, Sun's sequence of upgrades on Solaris will too.

Singer also wondered whether customers would have to upgrade to AIX 5L 5.3
to take advantage of new capabilities like multithreading support. IBM expects to have AIX 5L 5.3 for late
summer.

Singer told internetnews.com IBM's Power5 news means there is still a
lot of room for innovation. The executive said Sun has a three-pronged
attack in the chip space, noting that Sun plans to leapfrog past IBM's Power5 with its UltraSparc IVi and IIIi processors, due later this fall.

Later, Singer said the "Niagra" and "Rock" chips will move Sun up in the
"massive chip multi-threading" territory in a big way, with eight cores and
four threads per core. He also said Sun's APL processor agreement
with Fujitsu will help customers handle the load of mainframe migration
"going on around the world."

Moreover, Singer said the company already announced virtual servers with N1
Grid Partition for Solaris 10. While IBM's micro-partitioning capabilities
help Big Blue to catch up, Singer said Sun also has the ability to run UNIX
on Xeon and Opteron processors.

Still, Singer called IBM's Power5 news an "incremental move forward," and allowed that IBM's benchmarks were impressive, particularly because they
tested the gamut of SAP, PeopleSoft and Oracle applications and shied away
from traditional benchmarks that test the frequency of the processor.

"That is very much more what we think people should be looking at and that's
application throughput," Singer said. "We think it's a space that we will
dominate with our massive chip multi-threading."